When we lived in the bush 65 klm north of Gympie in a slice of paradise, 20 years ago, one of our first things was to get a solar panel on the roof. We went for a Solarhart and it was fitted easily, along with pressure pump and all bathroom and kitchen connections. in just one day.
It was BRILLIANT

There were 5 of us in the house - 3 kids with lots of washing and showers. One time we had cloudy weather for 3 days, and even after that time, the water was still tepid! we did not have electric backup.
It would frequently boil in the roof.
Ours was the first one in the bush and all the neighbours thought we were crackers - they said we should have purchased some more heiffers

Our next door neighbours (1 klm away) once showed us their new acquisition - a copper water boiler. They had to fetch the water, fetch the firewood, light it up and then wait for the water to be hot enough to start the washing. We said we were happy to get our hot water direct from the sun - at the turn of a tap........